Kidney transplant recipients are now benefiting from donor organs that do not match their blood type but are compatible and just as safe, according to a Vanderbilt University Medical Center study in the Journal of the American College of Surgeons.
The study's finding is significant because roughly 15 percent of the population has blood type B, which is more common in African-Americans, and those patients have historically been transplanted at lower rates due to a lack of available organs.
The Vanderbilt study shows that blood type B patients can receive blood type A2 kidneys with similar outcomes.
Lead author David Shaffer, MD, professor of Surgery and Chief of Kidney and Pancreas Transplant, said more than 400 of the roughly 1,000 patients on the Vanderbilt waitlist for a kidney are African-Americans.
"This is a significant move at Vanderbilt and our region as over 40 percent of our patients are African-Americans," Shaffer said. "It should improve access to transplants for our patient population."
The United Network for Organ Sharing (UNOS) has allowed centers to use blood group A2 kidneys for B recipients since December 2014 without obtaining a waiver, seeking to make more organs available to B patients while reducing disparities in wait times. Vanderbilt's study sought to determine the results of the policy change.
"Our study shows that the UNOS policy to increase access to kidney transplantation for minorities works," Shaffer said. "This is a significant option for centers to adopt to reduce the disparity and increase access to kidney transplants for blood group B recipients who are principally ethnic minorities."
The study analyzed outcomes at Vanderbilt from December 2014 through December 2017, including patient and graft survival, transplant wait time, serum creatinine and eGFR (estimated glomerular filtration rate), hospital costs, post-transplant anti-A titers, and their change relative to pre-transplant.
Even with the new availability, the study notes a recent UNOS analysis showed only 4.5 percent of waitlisted B recipients were registered as eligible for A2 donor kidneys, the result of issues with titers thresholds, patient eligibility and increased costs.
Transplant programs, regulators and payors will need to weigh improved access for minorities with the increased costs involved, study authors said.
Pre-transplant anti-A titer screening added total costs of $76,550 over the three-year study period, excluding additional coordinator time costs.
A2 to B had significantly higher mean transplant total hospital costs ($114,638 vs $91,697 for B to B transplantation) and mean hospital costs net organ acquisition costs ($42,356 vs $20,983).